We were asked about best practices for managing the RavenDB session (unit of work) in a .NET Core MVC application. I thought it is interesting enough to warrant its own post.

RavenDB’s client API is divided into the Document Store, which holds the overall configuration required to access a RavenDB and the Document Session, which is a short lived object implementing Unit of Work pattern and typically only used for a single request.

We’ll start by adding the RavenDB configuration to the appsettings.json file, like so:

	{
	"Database": {
	"Urls": [
	"https://a.rock-n.roll.ravendb.cloud",
	"https://b.rock-n.roll.ravendb.cloud",
	"https://c.rock-n.roll.ravendb.cloud",
	],
	"DatabaseName": "Jazz",
	"CertPath": "/mnt/config/jazz.pfx",
	"CertPass": null
	}
	}

view raw appsettings.json hosted with ❤ by GitHub

We bind it to the following strongly typed configuration class:

	public class Settings
	{
	public DatabaseSettings Database { get; set; }
	public class DatabaseSettings
	{
	public string[] Urls { get; set; }
	public string DatabaseName { get; set; }
	public string CertPath { get;set; }
	public string CertPass { get;set; }
	}
	}

view raw Settings.cs hosted with ❤ by GitHub

The last thing to do it to register this with the container for dependency injection purposes:

	public void ConfigureServices(IServiceCollection services)
	{
	var settings = new Settings();
	Configuration.Bind(settings);
	var store = new DocumentStore
	{
	Urls = settings.Urls,
	Database = settings.DatabaseName,
	Certificate = new X509Certificate2( settings.CertPath, settings.CertPass)
	};
	store.Initialize();
	services.AddSingleton<IDocumentStore>(store);
	services.AddScoped<IAsyncDocumentSession>(serviceProvider =>
	{
	return serviceProvider
	.GetService<IDocumentStore>()
	.OpenAsyncSession();
	});
	}

view raw configure.cs hosted with ❤ by GitHub

We register both the Document Store and the Document Session in the container, but note that the session is registered on a scoped mode, so each connection will get a new session.

Finally, let’s make actual use of the session in a controller:

	public class UsersController : Controller
	{
	private readonly IAsyncDocumentSession _session;
	public UsersController(IAsyncDocumentSession session)
	{
	_session = session;
	}
	public async Task<IActionResult> Index()
	{
	var users = await session.Query<User>().ToListAsync();
	return View(users);
	}
	}

view raw users.cs hosted with ❤ by GitHub

Note that we used to recommend having SaveChangesAsync run for you automatically, but at this time, I think it is probably better to do this explicitly.